Hiya Guys

when i run a surfacing gcode on my taig I get lines between each pass, the endmill is over running the previous line so it's not that.

Im pretty damn sure it is down to adjustment that is needed on the Z axis, anyone know what and how it needs adjusting?

Thanks

DJH

after you make a couple passes back and forth, if you rub your finger across the passes perpindicularly to the direction of the passes, can you feel them, or are you just seeing them.. being new to all of this myself, the first few times that i did a surfacing pass back and forth back and forth, i looked at it and it looked like it was rough, but when i rubbed my finger across the passes they were silky smooth, it was just the light playing tricks on my eyes...

if your finger feels the difference in the passes, is it like this -_-_-_ or like this / / / /
if its the first then there might be some slack or backlash in the machine, if its the second then the endmill isnt perfectly straight up and down, and there may be some adjustments you need to make....

how deep and how fast are you cutting, and in what material with what endmill? going too agressive with your cuts might reveal some flexing in the machine, and the only way that i know to fix that is to take less agresive cuts...

just my .02

Dull endmill, poorly ground endmill, head out of tram with y-axis, head out of tram with x-axis, weird alloy, lack of coolant, head backlash not set correctly. All of these can cause it. But until you determine that the surface actually isn't flat, it's all guesswork. Lay a straightedge (a real, good straightedge) along the work and see if you can see light between the milled steps.

Hiya

I can definatley feel a very slight ripple parallel to the X axis (the long one)

It is during the cut it happens all the way along, very uniform looking (looks very nice in fact :P ) so i don't beleive it is backlash as it only happens ont he long straights.

I am cutting in 6082 aluminium, does not matter whether I cut at 5 ipm or 50 ipm

im making very small cuts depth wise (0.0050"), the end mill is a new 8mm
endmill (carbide, was quite expensive) and I get the same problem if I use other smaller endmills (just lots more lines)

I get one line per pass and it seem that it is at the back of the mill, as iff the Z column is tiliting forward.

I have a Kress spindle, but had the same problem with the original er-16 spindle.

it's not out by much, but enough to notice, tramming sounds like ti would be a real pain and not much fun (i know nothing about tramming)

Is that the only way to adjust it? do i need a dial test indicator to measure the ridge height?

Thanks as always

DJH

Do you have the stock Vise?

-Jason

Yup, the only thing to do is to shim the dovetail mount piece at the bottom with a .001-.002 shim, and see if that helps. You need a test indicator to check the whether you have it trammed or not, against a parallel or 1-2-3 block on the bed of the mill. But if it doesn't bother you, don't worry about it.
Tramming can make you crazy, but ultimately you will need to learn how to do it...

Hiya

I get one line per pass and it seem that it is at the back of the mill, as iff the Z column is tiliting forward.

it's not out by much, but enough to notice, tramming sounds like ti would be a real pain and not much fun (i know nothing about tramming)

Is that the only way to adjust it? do i need a dial test indicator to measure the ridge height?
DJH

No I don't have a Taig vice, tho would like one.

I guess I could use feeler gauges for the shims?

I intend to get some parallels anyway so thats fine, ive never understood how 123 blocks were used or what for?

I don't have a dovetail mount, but I guess i could do the same with my current mount

Thanks

DJH

Well the stock vise I found not to be good at all. I thought my mill was all out of alignment but when I clamped down my work. Was smooth and nicely cut. The stock vise is not big enough for anything really and i did not like the finish that the mill gave me when my worked was being used by it.

-Speed

ok have tried a new piece of code that cuts it starting from the center and kinda sprials out in a square way, im sure you get what I mean, no the lines parallel to the Y axis are a lot smoother ( I did a much finer cut)

but the lines parallel to the X are decidedly rough, this is just becoming a pain now.

I guess i need a dti, mount on bed up against spindle mount and see what difference there is in it/s travel?

DJH

I had a very similar problem on my machine. It turned out to be with the Z axis not square to the Y + X. It was noticeable but not bad on metal, but wood really brought the problem out.

Tram it, your head is out.

Get a test indicator, put it in the widest mount you can find and put that in a collet in the head. Touch the bed of the mill with the indicator with the tip of the test indicator and spin it around. You'll find one side is higher than the other. If it's out along the X, you're fine, just get a wrench, loosen the huge bolt at the back a bit and get it straight up and down. Test the bed again, it won't be straight, but it should be straighter. Get a soft mallet and crank down a bit more on the nut at the back. Give the beam a tap in the right direction, test the bed again with the indicator and keep tapping and tightening until the needle doesn't move. Now the machine is in tram along the X. If it's out along the Y you're kinda screwed, you'll have to shim or scrape down the dovetail holding the head to the Z saddle so that the head is perfectly perpendicular. That's unlikely though. If it is out along the Y a bit, then check for chips under the dovetail. One little spec of anything will cause the dovetail to not tighten down straight.